1. Field of Invention
This invention relates to a ski boot having a rigid plastic shell base, and an interchangeable sole portion for controlling the global wedging angle of the boot. In particular, the invention relates to ski boots having soles suitable both for walking and for attachment to ski bindings, and designed to meet certain criteria of international standards selected to assure safe operation of a binding which constitutes the functional interface between a boot and a ski.
2. Discussion of Background Material
The number of skiers engaged in alpine skiing has recently increased; and this increase has aggravated the problem of accommodating ski boots to the morphology of the legs of a certain class of such skiers such that the boots can be used with a maximum of comfort and safety.
The proper global wedging angle of a boot, which is the angle between a plane perpendicular to the top surface of a ski and the direction imposed on the lower leg of the wearer by the upper of the boot, should depend upon the morphological orientation of the leg of a skier. Effecting modification of the global wedging angle to accommodate different skiers is a problem addressed by mechanisms disclosed in U.S. Pat. Nos. 3,922,800, 3,747,235, and 3,885,329; and in French Patent No. 2,166,677. These patents relate to means for orienting the foot of a skier by modifying the orientation of the upper of the boot with respect to the top surface of the ski. Other publications teach adding shims to the sole of a boot to effect a predetermined angular wedging of the upper.
U.S. Pat. No. 4,078,322 discloses a ski boot having removable and interchangeable sole portions. This expedient makes it possible to utilize different wedging angles for a given shell base of a ski boot which is designed for use with conventional bindings by reason of the provision of different sets of sole portions. In this patent, modification of the wedging angle of the boot is achieved only because of the interchangeability of sole portions selected from a stock thereof having angles of inclination lying within a predetermined range. Unfortunately, knowledge of the desired angle of inclination is not always immediately available to a skier. On the other hand, if a skier decides to interchange the sole portion from his right boot with the sole portion from his left boot, the angular wedging is automatically changed from an orientation towards the exterior of his knees to an orientation towards the interior thereof, or vice versa. This does not resolve the problem of morphological adaptation which may become even further aggravated by this exchange.
It is therefore an object of the present invention to improve the angular wedging system of a ski boot having removable sole portions by allowing for the interchangeability of the sole portions of the right boot with the left boot of a single pair of boots such that the amount of angular wedging varies on the interior of a given morphological orientation of the legs of a skier.